Wearable multiphasic cardioverter defibrillator system and method

ABSTRACT

A wearable, multiphasic cardioverter defibrillator system and method are provided.

PRIORITY CLAIMS

This application claims priority to under 35 USC 120 and the benefitunder 35 USC 119(e) to U.S. Provisional Patent Application Ser. No.61/835,459, filed on Jun. 14, 2013 and titled “Wearable MultiphasicCardioverter Defibrillator System And Method”, the entirety of which isincorporated by reference herein.

FIELD

The disclosure relates generally to methods and arrangements relating tomedical devices. More specifically, the disclosure relates to thesystems and methods used in external defibrillators and in a preferredembodiment to wearable cardioverter defibrillators.

BACKGROUND

A primary task of the heart is to pump oxygenated, nutrient-rich bloodthroughout the body. Electrical impulses generated by a portion of theheart regulate the pumping cycle. When the electrical impulses follow aregular and consistent pattern, the heart functions normally and thepumping of blood is optimized. When the electrical impulses of the heartare disrupted (i.e., cardiac arrhythmia), this pattern of electricalimpulses becomes chaotic or overly rapid, and a Sudden Cardiac Arrestmay take place, which inhibits the circulation of blood. As a result,the brain and other critical organs are deprived of nutrients andoxygen. A person experiencing Sudden Cardiac Arrest may suddenly loseconsciousness and die shortly thereafter if left untreated.

The most successful therapy for Sudden Cardiac Arrest is prompt andappropriate defibrillation. A defibrillator uses electrical shocks torestore the proper functioning of the heart. A crucial component of thesuccess or failure of defibrillation, however, is time. Ideally, avictim should be defibrillated immediately upon suffering a SuddenCardiac Arrest, as the victim's chances of survival dwindle rapidly forevery minute without treatment.

There are a wide variety of defibrillators. For example, ImplantableCardioverter-Defibrillators (ICD) involve surgically implanting wirecoils and a generator device within a person. ICDs are typically forpeople at high risk for a cardiac arrhythmia. When a cardiac arrhythmiais detected, a current is automatically passed through the heart of theuser with little or no intervention by a third party.

Another, more common type of defibrillator is the automated externaldefibrillator (AED). Rather than being implanted, the AED is an externaldevice used by a third party to resuscitate a person who has sufferedfrom sudden cardiac arrest. FIG. 19 illustrates a conventional AED 1900,which includes a base unit 1902 and two pads 1904. Sometimes paddleswith handles are used instead of the pads 1904. The pads 1904 areconnected to the base unit 1902 using electrical cables 1906.

A typical protocol for using the AED 1900 is as follows. Initially, theperson who has suffered from sudden cardiac arrest is placed on thefloor. Clothing is removed to reveal the person's chest 1908. The pads1904 are applied to appropriate locations on the chest 1908, asillustrated in FIG. 19. The electrical system within the base unit 1902generates a high voltage between the two pads 1904, which delivers anelectrical shock to the person. Ideally, the shock restores a normalcardiac rhythm. In some cases, multiple shocks are required.

Although existing technologies work well, there are continuing effortsto improve the effectiveness, safety and usability of automatic externaldefibrillators. Accordingly, efforts have been made to improve theavailability of automated external defibrillators (AED), so that theyare more likely to be in the vicinity of sudden cardiac arrest victims.Advances in medical technology have reduced the cost and size ofautomated external defibrillators (AED). Some modern AEDs approximatethe size of a laptop computer or backpack. Even small devices maytypically weigh 4-10 pounds or more. Accordingly, they are increasinglyfound mounted in public facilities (e.g., airports, schools, gyms, etc.)and, more rarely, residences. Unfortunately, the average success ratesfor cardiac resuscitation remain abysmally low (less than 1%).

Such solutions, while effective, are still less than ideal for mostsituations. Assume, for example, that a person suffers from a cardiacarrest in an airport in which multiple AEDs have been distributed. Thevictim's companion would nevertheless have to locate and run towards thenearest AED, pull the device off the wall, and return to the collapsedvictim to render assistance. During that time, precious minutes may havepassed. According to some estimates, the chance of surviving a suddencardiac arrest is 90% if the victim is defibrillated within one minute,but declines by 10% for every minute thereafter. A defibrillator designthat reduces the time to defibrillation by even two to three minuteswill save more lives.

An additional challenge is that a sudden cardiac arrest may take placeanywhere. People often spend time away from public facilities and theirhomes. For example, a sudden cardiac arrest could strike someone whilebiking in the hills, skiing on the mountains, strolling along the beach,or jogging on a dirt trail. Ideally, an improved AED design would becompact, light, and resistant to the elements and easily attached ordetached from one's body. The typical AED design illustrated in FIG. 19,which includes a sizable console or power unit whose form factor issimilar to that of a laptop or backpack, seems less than ideal for theoutdoors and other rigorous environments.

New and improved designs are allowing AEDs to become ultra-portable andhence to able to be easily carried by an at-risk person as they go aboutall of their daily activities and thus are able to be close at hand whena sudden cardiac arrest strikes outside of a hospital environment or ahigh traffic public area with a Public Access Defibrillator.

There are also improvements being made in the area of device usabilityand ease of operation for untrained bystanders. As noted above, everyminute of delay or distraction can substantially decrease the victim'sprobability of survival. As a result, it is generally beneficial tostreamline the operation of the external defibrillator so that a user ofthe defibrillator, who is presumably under substantial mental duress,can focus his or her attention on a few, key variables.

Another type of defibrillator is the Wearable Cardioverter Defibrillator(WCD). Rather than a device being implanted into a person at-risk fromSudden Cardiac Arrest, or being used by a bystander once a person hasalready collapsed from experiencing a Sudden Cardiac Arrest, the WCD isan external device worn by an at-risk person which continuously monitorstheir heart rhythm to identify the occurrence of an arrhythmia, to thencorrectly identify the type of arrhythmia involved and then toautomatically apply the therapeutic action required for the type ofarrhythmia identified, whether this be cardioversion or defibrillation.These devices are most frequently used for patients who have beenidentified as potentially requiring an ICD and to effectively protectthem during the two to six month medical evaluation period before afinal decision is made and they are officially cleared for, or denied,an ICD.

The current varieties of defibrillators available on the market today,whether Implantable Cardioverter Defibrillators (ICDs) or AutomaticExternal Defibrillators (AEDs) or any other variety such as WearableCardioverter Defibrillators (WCDs), predominantly utilize either aMonophasic waveform or Biphasic waveform for the therapeuticdefibrillation high-energy pulse or for the lower energy cardioversionpulse. Some clinical research has been done into the benefits ofTriphasic waveforms for the therapeutic defibrillation high-energypulse, but as of yet no device has been brought to market using thistype of waveform.

Each manufacturer of defibrillators, for commercial reasons, has theirown unique and slightly different take on waveform design for theirdevices' pulses. Multiple clinical studies over the last couple ofdecades have indicated that use of a Biphasic waveform has greatertherapeutic value to a patient requiring defibrillation therapy, than aMonophasic waveform does, and that Biphasic waveforms are efficacious atlower levels of energy delivery than Monophasic waveforms.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an external patient contact assembly exhibiting bothsensors and electrodes.

FIG. 2 illustrates the reverse side of the assembly in FIG. 1 exhibitingthe internal electrical contacts and anchor locations.

FIG. 3 illustrates various shaped sensor and electrode components of theassembly in FIG. 1 before and after being swaged.

FIG. 4 illustrates both sides of an external patient contact assemblywhile in a flexed position.

FIG. 5 illustrates the contact between a patient's skin and the patientcontact assembly of FIG. 4.

FIG. 6A illustrates a multiphasic waveform system with a plurality ofindependent subsystems each with its own energy reservoir and energysource.

FIG. 6B illustrates more details of each subsystem of the multiphasicwaveform system.

FIG. 6C illustrates a typical H-bridge circuit.

FIG. 6D illustrate an H-bridge circuit integrated into the multiphasicwaveform system

FIG. 7 illustrates defibrillator pulse waveforms including a typicalbiphasic pulse waveform and four novel biphasic pulse and multiphasicpulse waveforms.

FIG. 8 illustrates circuitry and energy source/reservoir module withstrap attachment fixtures.

FIG. 9 illustrates a flexed circuitry and energy source/reservoir modulewith strap attachment fixtures of FIG. 8.

FIG. 10 illustrates a couple of flexed circuitry and energysource/reservoir modules with straps for attachment to a patient's torsoand/or limbs.

FIG. 11 illustrates the components and flexible circuitry within acircuitry and energy source/reservoir module in both flexed andnon-flexed states.

FIGS. 12A and 12B illustrate a space within a circuitry and energysource/reservoir module for the components and flexible circuitry thatis used in the module.

FIG. 13 illustrates how a circuitry and energy source/reservoir modulewith strap attaches to a patient's torso and/or limb.

FIG. 14 illustrates an embodiment with two modules, both mounted on theexterior of the upper limbs and electrically connected.

FIG. 15 illustrates an embodiment with two modules, both mounted on theinterior of the upper limbs and electrically connected.

FIG. 16 illustrates an embodiment with two modules, both mounted on thetorso under the upper limbs and electrically connected via the mountingstrap(s).

FIG. 17 illustrates an embodiment with three modules, all mounted on thetorso of the patient and electrically connected via the mountingstrap(s).

FIG. 18 illustrates an embodiment with two modules, one mounted on thetorso of the patient and one mounted on the upper limb and electricallyconnected.

FIG. 19 diagrammatically illustrates an example of a conventionalexternal defibrillator.

DETAILED DESCRIPTION OF ONE OR MORE EMBODIMENTS

Wearable Cardioverter Defibrillators on the market today are still bulkyand uncomfortable for the patients to wear. They utilize a single sourceof energy in a box that attaches to the wearable garment (containing thesensors and the electrodes) and the energy source box normally rides onthe hip. These devices are heavy and uncomfortable to wear and afrequent source of complaints from patients. These existing WCDs alsouse reservoirs of liquid conductive hydrogel which are deployed onto thepatient's skin in contact with the electrodes before a therapeutic shockis delivered in order to reduce the electrode-to-patient impedance.These reservoirs need to be refilled/replaced and the hydrogel needs tobe cleaned off the patient on each occasion, both actions of which arean inconvenience or a hassle to the patient and which restrict the easeof using the device in normal daily life. The waveform used in theseexisting WCDs was originally a monophasic waveform and has now beenreplaced with a standard biphasic one. This provides a limited range oftherapeutic waveforms that can be delivered to a patient.

These existing WCDs also incorporate an override button which a patientcan use to prevent unnecessary shocks from being delivered when alertedby an audible alarm that such a shock is about to be delivered. Thereare medical, practical and commercial needs to make new WCDs smaller andmore flexible, more comfortable and more discrete for patients to wearas they go about their daily lives. The most effective way in which toaccomplish this, which is disclosed below, has the circuitry and theenergy source/reservoir that are re-distributed from one largecontainer/enclosure into several smaller containers each with their owncircuitry and energy source/reservoir and which can be mounted invarious places on the body of the patient with the sensors andelectrodes and hence the system can be made smaller and more flexible,more comfortable and more discrete.

The disclosed system also may use one or more Multi-part Non-uniformPliable Contact Assemblies that ensures that the optimal electrodecontact is maintained with the patient and hence that theelectrode-to-patient impedance is minimized without requiring that thepatient be dowsed in liquid conductive hydrogel before administering ashock. The system may employ a mix of sensors, such as ECG sensors andLED pulse detectors, rather than the normal use of just ECG sensors,which means that the accuracy of the detection of shockable arrhythmiascan be significantly improved and hence the incidence of unnecessaryshocks can be significantly reduced and hence the need for a patient touse the override button is reduced.

In one embodiment, the system may use the upper arms of a user as thelocations for the circuitry and energy source/reservoir modules whichmeans that the conduction paths for the therapeutic current to reach theheart are of lower impedance than the normal transthoracic conductionpathways. Lowering the patient's impedance means that the device isrequired to store and deliver less energy and hence the system can bemade smaller and more flexible, more comfortable and more discrete.

The system may make use of a plurality of circuitry and energysource/reservoir modules in order to deliver variable amplitudemultiphasic waveforms and hence maximize the efficaciousness of thetherapeutic shock protocol. In one embodiment, the system may use fourmodules in order to provide the ability to perform orthogonal shockingsuch that it maximizes the percentage of cardiac tissue that isdepolarized (Encircling Overlapping Multipulse Shock Waveforms forTransthoracic Defibrillation; Pagan-Carlo, Allan et al.; December 1998)and hence maximize the efficaciousness of the therapeutic shockprotocol. In another embodiment, the system may use six modules in orderto provide the ability to deliver overlapping multiphasic waveforms(Encircling Overlapping Multipulse Shock Waveforms for TransthoracicDefibrillation; Pagan-Carlo, Allan et al.; December 1998) and hencemaximize the efficaciousness of the therapeutic shock protocol.

FIG. 1 illustrates the external patient contact assembly 100 exhibitingboth sensors and electrodes wherein the assembly is a multi-partnon-uniform pliable contact assembly. The assembly may be made of apliable substrate 101 with an embedded set of one or more electrodecontact elements 104, 105, in various shapes such as bars & buttons, andan embedded set of one or more sensor contact elements 103, 106, invarious shapes such as bars & buttons. The various contact elements ofthe Multi-part Non-uniform Pliable Contact Surface 100 may vary in shapeand number to suit the specific need for a given embodiment of thesystem and its use to provide the best results.

The one or more Electrode Contact Elements (104 and 105) may be acombination of highly conductive Bars (104) and Buttons (105) thatprovide an interface to the skin of a patient for delivery of the highenergy multi-phasic therapeutic shock pulse or lower energycardioversion pulse. The one or more Sensor Contact Elements (103 and106) may be a combination of conductive Bars (103) and Buttons (106)that provide an electrical interface to the skin of the patient for thepurpose of measuring the weak electrical signals of the heart (ECG), inorder to detect abnormal or irregular heart rhythms. Additionally, inone embodiment, some of the Sensor Contact Elements (103 and 106) may beother types of sensors, such as optical sensors utilizing LEDs in orderto measure the physical blood flow within the body. By combining the ECGmeasurements with the physical pulse measurements, the assembly 100 canimprove on the speed and accuracy of detection of the abnormal orirregular heart rhythms which are shockable and hence reduce the chanceof delivering inappropriate therapeutic shocks to the patient. The oneor more electrode contact elements 104, 105 and the one or more sensorcontact elements 103, 106 may be arranged in various differentconfigurations on the assembly 100, such as the configuration shown inFIG. 1 in which the sensor contact elements are located across an upperportion of the assembly and the electrode contact elements are locatedacross a lower portion of the assembly.

The materials that the electrode contact elements are made out of arehighly conductive and likely to be metallic in nature such as stainlesssteel, gold, or gold plated copper, silver or another suitable basemetal.

The materials that the ECG sensor contact elements are made out of arehighly conductive and likely to be metallic in nature such as stainlesssteel, gold, or gold plated copper, silver or another suitable basemetal. Other types of sensors, such as the LED pulse sensors, will bemade of different materials. The LED sensors will be made of anoptically clear material such as glass, sapphire, plastic or a glasspacified SiGe semiconductor (or other appropriate technology) mounted insuch a way as to be in contact with the patient's skin. Other sensortypes, such as those for body temperature, skin moisture, acceleration,or other physical properties will be made of the materials relevant tothe specific need involved and these are likely to be well known in theart for each.

FIG. 2 shows the back side for the Multi-part Non-uniform PliableContact Assembly (100). On the back side, the conductive Electrode andSensor Contact Elements (104 and 105, 103 and 106) are attached to oneor more Pliable Substrates (101 and 102) that allow the assembly 100with the contact elements to bend and flex. The backside of the assembly100 may also have one or more circuit assemblies 202, 203 thatinterconnect the conductive Electrode and Sensor Contact Elements (104and 105, 103 and 106.) The Electrode and Sensor Contact Elements (104and 105, 103 and 106) are installed and through a swage process, theends of the contact elements are rolled over forming a solid physicaland electrical contact to the Interconnecting Circuit Assemblies (202and 203). In the embodiments where they are used, the alternative(optical and non-metallic) Sensor Contact elements are attached asappropriate to their specific purposes.

FIG. 3 shows the details of the conductive Electrode and Sensor ContactElements (104 and 105, 103 and 106). A back side of the Electrode andSensor Contact Elements (301 and 303, 304 and 305) are shown and theresult of the swage process is illustrated. An end of the contact (306)is shaped as a hollow tube, that is rolled over through the use of a dieand forms the end into an expanded disk (302) for each of the contactelements. The expanded disks 302 of each contact element may then besandwiched between the Pliable Substrates (101 and 102) and theInterconnecting Circuit Assemblies (202 and 203), forming the physicaland electrical connections.

FIG. 4 illustrates both sides of the external patient contact assembly100 while in a flexed position. The assembly 100 may be fabricated onthe set of Pliable Substrates (101 and 102). The outer Pliable Substrate(101) is made of a tightly woven material that is hypo-allergenic andgentle and yet also very strong. An example of this is a silicon, nylonreinforced material, although suitable new materials are being createdall of the time. This material will constitute the outer surface of theAED High Energy Source/Reservoir circuitry as shown in FIGS. 8 and 9.The inner Pliable Substrate (102) may be made of a sheet of flexiblematerial, such as reinforced flexible nylon. The inner Pliable Substrate(102) provides stabilization and precise locations for the Electrode andSensor Contact Elements (104 and 105, 103 and 106) and a stable backingstructure for the Interconnecting Circuit Assemblies (202 and 203). TheMulti-part Non-uniform Pliable Contact Assembly (100) is shown in FIG. 4in a curved state. The assembly 100 may be flexed in all axes. Theassembly 100 supports the ability of the contact assembly 100 tomaximize contact with the patient when being used to deliver a shock tothe patient, such as by a wearable AED.

FIG. 5 illustrates the contact between a patient's skin and the patientcontact assembly (patient interface). As shown in FIG. 5, the front(contact with Patient) surfaces of the Electrode and Sensor ContactElements (104 and 105, 103 and 106) have gentle curved smooth surfaces,providing comfort to the Patient skin, while allowing the pliabledermis/epidermis layers to deform, wraparound and conform to theembedded shapes of the Bar and Button contacts, as shown in FIG. 5. TheElectrode and Sensor Contact Elements (104 and 105, 103 and 106) areshown in contact with the Patient's skin, 700. The pliable nature of thePatient's dermis/epidermis layers effectively fills in the gaps betweenthe Bar and Button Contact Elements, in addition the flexible nature ofthe Pliable Contact Assembly (100) increases and maximizes the contactareas with the Patient by conforming to the specific curvatures of thebody.

FIG. 6A is a block diagram of a multiphasic waveform system with aplurality of independent subsystems each with its own energy reservoirand energy source that may be used as part of the wearable AED. Thepulse system 10 is not limited to any particular number of energyreservoirs (such as capacitors) or energy sources (such as batteries).The pulse system 10 may have a plurality or “n” number (as many aswanted) subsystems 12, 14 that together can be utilized to provide thevarious multiphasic waveforms, examples of which are shown in FIG. 7 anddescribed below. In the example implementation shown in FIG. 6A, theremay be two sides, such as side A and side B as shown, and each side mayhave one or more of the subsystems 12, 14 and each subsystem maygenerate a pulse (that may be a positive pulse or a negative pulse.) Thetwo or more subsystems 12, 14 permit the system to shape the variouscharacteristics of a positive phase of the waveform separately from theshaping of the characteristics of the negative phase of the waveform andvice versa. The above described functions may be accomplished throughthe use of a fast switching high-energy/voltage switch system asdescribed below.

Each subsystem 12, 14 of each side, as shown in FIG. 6B, may have acontrol logic and heart rhythm sense component 20 (that is connected toa similar component on the other side by a digital control link 30 asshown in FIG. 6A) that may be also coupled to a high voltage switchingsystem component 22. The high voltage switching system component 22 maybe implemented using either analog circuits or digital circuits or evensome hybrid of the two approaches. Furthermore, the high voltageswitching system component 22 may be implemented through the use ofmechanical or solid-state switches or a combination of the two. As shownin FIG. 6D, the high voltage switching system component 22 may beimplemented using one or more semiconductor circuits, such as theinsulated gate bipolar transistors. The high voltage switching systemcomponent 22 may be coupled to an energy reservoir 24 and the energyreservoir 24 may be coupled to a power source 26, such as a battery. Theenergy reservoir 24 may further comprise a reservoir 24A, such as forexample one or more capacitors or a capacitor array, and a high voltagegenerator 24B. The energy reservoir 24 may also be coupled, by a highvoltage return line 32 to the other side of the system as shown in FIG.6A. The high voltage return 32 electrically completes the circuit and ispresent in existing defibrillators, but in a slightly different formsince in the existing style of devices it is split into two parts: inthe form of the two leads which go from the main defibrillator device tothe internal or external surface of the patient.

The control logic and heart rhythm sense component 20 is well known inthe art and the component analyzes the ECG signals from the patient fortreatable arrhythmias and then chooses to shock the patient when atreatable arrhythmia is detected, along with guiding the operatorthrough both visual and audible means through this process when thedevice is of the external automated variety. The control logic and heartrhythm sense component 20 also may control and shape the therapeuticpulse as it is delivered from the energy reservoir and ensures that itis as optimal as possible for the individual patient. In theimplementations shown in FIG. 6A, the control logic and heart rhythmsense component 20 may generate the therapeutic pulse using the one ormore groups of subsystems since each subsystem may have its own controllogic 20 (so that each of them can control just the portion/phase of thepulse/waveform that they deliver. This provides a much higher level ofcontrol over what range of waveform shapes can be used/delivered,including many that are not possible with the existing devices. Thisalso provides better weight and size distribution, as well as size andweight reductions, and the ability to have the devices look radicallydifferent and be handled in very different ways—ones that are much moreoperator intuitive. The disclosed system also provides a much higherlevel of redundancy and fault mitigation for the device embodiments thatuse it.

In one implementation, each control logic in each subsystem may have acircuit that can be used to adjust the shape of each portion of thetherapeutic pulse. The circuit, may be for example, an array ofresistors of various strengths and switches so that one or more of theresistor may be selected (as an array of selectable resistors) that canoptimize and alter an RC constant of a subsystem's pulse phasegenerating circuitry in order to dynamically shape one or more pulsephases.

In some embodiments of the system, the system may provide for therecharging of individual energy reservoirs by the energy sources duringtimes (including inter-pulse times) that an individual energy reservoiris not selected for discharge as shown in FIG. 6A. This provides theopportunity to interlace equivalent amplitude initial multiphasic pulsesutilizing several different high energy reservoirs as shown in FIG. 7.Alternatively, each module may have one of a rechargeable or replaceableenergy sources or a combination of the two. In some implementations, theeach module may contain sufficient energy for only a limited number oflife saving shocks.

In one implementation, the system 10 has side A that may deliver one ormore of a Positive phase waveform of the Multiphasic therapeutic pulseand Side B may deliver one or more of a Negative phase waveform of theMultiphasic therapeutic pulse. As shown in FIG. 6A, the subsystems maybe coupled to the patient 16 by one or more high voltage leads and oneor more sense leads wherein the high voltage leads deliver thetherapeutic pulse and the sense leads are used to detect the heartbeatby the control unit.

The system 10 may either be pre-programmed to use a specific singlemultiphasic pulse shape, according to which one is shown to be mostefficacious in clinical lab testing/trials, or else it may select thebest one for a given purpose from a lookup table where they are listedaccording to their suitability for optimally resolving different typesof arrhythmia that are being screened for and identified or for thedifferent treatments as described above. Regardless, the system andmethod allows the use and application of a much wider range of pulseshapes than has been previously possible and this will allow the deviceswhich use this invention to keep up with clinical developments aswaveforms continue to be improved.

FIG. 6C illustrates a typical H-bridge circuit 300 and FIG. 6Dillustrates an H-bridge circuit concept used in the multiphasic waveformsystem. As shown in FIG. 6C, an H-bridge circuit is a known electroniccircuit that enables a voltage, such as Vin, to be applied across aload, M, in either direction using one or more switches (S1-S4) (seehttp://cp.literature.agilent.com/litweb/pdf/5989-6288EN.pdf that isincorporated by reference herein for additional details about theH-bridge circuit.) As shown in FIG. 6C, the H-bridge circuit may have afirst portion 302 and a second portion 304 that form the completeH-bridge circuit.

As shown in FIG. 6D, the H-bridge circuit may be part of the controlcircuits or switching systems shown in FIGS. 6A and 6B. The load of theH-bridge circuit in the multiphasic system is the patient 16 (shown hereas having the industry simulation standard resistance of 50 ohms, butwhich can vary between 20 and 200 ohms with real patients) to which thetherapeutic pulse is going to be applied to provide treatment to thepatient. The treatment to the patient, depending on the power and/orenergy level of the therapeutic pulse may be for cardiac pacing,cardioversion, defibrillation, neurological therapy, nerve therapy ormusculoskeletal therapy. Each side of the multiphasic system maygenerate its energy as described above and an H-bridge circuit 400 maybe used to apply two (or more) unique energy sources to the single load.In the example shown in FIG. 4, each side of the system (such as side Aand side B shown in FIGS. 6A and 6B) may have a portion 402, 404 of theH-bridge so that the multiphasic system has a complete H-bridge circuitthat is combination of portions 402, 404. The multiphasic system maythen be used to deliver the therapeutic pulse through defibrillationpaddles, such as Paddle A and Paddle B as shown in FIG. 4) to thepatient.

Each portion 402, 404 of the H-bridge has its own energy source, 1600VDC in the example in FIG. 6D. In each portion of the H-bridge, theenergy source may be switched using switches 406, 408 to make contactwith the patient at a separate but specific time. The switches for eachportion may be part of the switching system shown in FIGS. 6A and 6B. Inthe example in FIG. 6D, each portion may have two switches and eachswitch may be a commercially available insulated-gate bipolar transistor(IGBT.) Each switch may be controlled by a separate trigger signal asshown to discharge the energy to the patient. This provides for the twoor more energy sources to discharge their energy to the load (patient)at a precise time, generating a resulting Biphasic discharge pulse orother therapeutic pulse shapes (examples of which are shown in FIG. 7)as defined for an application, or therapeutic condition.

FIG. 7 illustrates the pulse waveform capabilities of the dynamicallyadjustable multiphasic defibrillator pulse system. Pulse 701 shows atypical Biphasic Defibrillator Pulse with an exponentially decliningamplitude, and 702; 703; and 704 show the capability of the dynamicallyadjustable multiphasic defibrillator pulse system to produce Biphasicand Multiphasic waveforms that have the following characteristics: equalamplitude in the initial positive and negative phases of the pulse(702), to produce a waveform with an initial lower amplitude positivephase and an initial higher amplitude negative phase pulse (703) andalso to produce a waveform with equal amplitude in the initial positiveand negative phases of the pulse and multiple positive phase to negativephase pulse transitions (704). 705 shows the ability for the pulsesystem to provide a waveform with equal amplitude in all of the positiveand negative phases of the pulse and with multiple positive phase tonegative phase transitions throughout the entire therapeutic pulseevent.

These waveforms can start with either a positive or a negative polarityphase. Phases subsequent to the first phase can also be of a lowerleading edge amplitude than would be expected from the trailing edge ofthe prior phase. The tilt (or rate of the phase's signal decay) can alsovary from phase to phase through the use of varying capacitor ratingswithin the capacitors constituting each energy reservoir or else throughthe use of suitable resistors.

FIG. 8 illustrates a circuitry and energy source/reservoir module 800with strap attachment fixtures. The wearable multiphasic system may haveone or more of the circuitry and energy source/reservoir module 800attached to the body of the patient. Each of the one or more circuitryand energy source/reservoir modules (800), is housed in a pliable andflexible outer shell (801), shown in two different embodiments in FIGS.8 and 9. The outer shell (801) may be made of a material that is highlydurable and flexible, similar to the woven nylon found in aviator/spacesuits. The mounting bands (901) shown in FIG. 10 are attached to rings(802) that are connected to the housing of the outer shell (801). TheMulti-part Non-uniform Pliable Contact Assembly (100) and the Electrodeand Sensor Contact Elements (104 and 105, 103 and 106) are, in oneembodiment, incorporated within the flexible outer shell (801). In someimplementations, each module 800 may have an adhesive on or around thepatient interface assembly (including the multi-part non-uniform pliablecontact assembly (100) and the electrode and sensor contact elements(104 and 105, 103 and 106)) to help the patient interface assemblyremain in place on the patient while being worn by the patient as shownin FIGS. 14-18.

FIG. 9 shows an embodiment with the ability for each of the circuitryand energy source/reservoir modules (800) to conform to the patients'body curves. FIG. 10 illustrates a couple of flexed circuitry and energysource/reservoir modules with straps for attachment to a patient's torsoand/or limbs. In one or more of the embodiments of the system, thehousing/shell 800,801 (see FIGS. 8-10 and 12A and 12B for differentexamples) may be waterproof so that the circuitry and elements in thehousing/shell are protected from water damage.

FIG. 10 shows one of the plurality of circuitry and energysource/reservoir modules (800) with a mounting band (901) attachedwherein the mounting band may have different sizes. The bands ofdiffering sizes allow for mounting each of the plurality of circuitryand energy source/reservoir modules (800) to various locations on thepatient. In one embodiment, the wearable multiphasic AED system may haveat least two such modules (800), as shown in FIG. 10, to constitute afunctional Wearable Cardioverter Defibrillator. However, the embodimentsof the system are not limited to the use of just two modules 800, asthere can be 1 to N number of modules in various embodiments of thesystem wherein N may be between 1 and 100.

A reference high voltage return lead and a digital control link (1405)shown in FIGS. 6 and 14-18, connects the plurality of circuitry andenergy source/reservoir modules (800) together in whatever connectioncombinations are therapeutically desirable. The Digital Control link1405 connects the Control Logic & Heart Rhythm management systems of themodules (800) together and coordinates the sensing and therapeuticaction decisions and various other Automated External Defibrillator orWearable Cardioverter Defibrillator functions. The High Voltage returnlead(s) provide the reference and return electrical path for theTherapeutic shock pulse. FIG. 11 illustrates the components and flexiblecircuitry within a circuitry and energy source/reservoir module 1100 inboth a flexed state and a non-flexed state. The high energysource/reservoir (1100) is made up of one or more energy reservoirs1103, such as one or more capacitors, a high voltage generator (1105), ahigh voltage switching system (1101), one or more energy sources 1102,such as one or more batteries and a control logic & heart rhythmsense/management control system (1104). All of these components orsubsystems are well known in the art. The High Energy Source/Reservoirmay be constructed of discreet components attached and interconnectedthrough a Flex circuit board that allows the High EnergySource/Reservoir to conform with the Multi-part Non-uniform PliableContact Assembly (100) and with the module (800) to the patient's body.FIGS. 12A and 12B show the High Energy Source/Reservoir (1100), withinthe module (800) in which the other side of the module 800 has theassembly 100.

FIG. 13 illustrates how a circuitry and energy source/reservoir module800 with strap 901 attaches to a patient's torso and/or limb 1300. Inthis embodiment the patient would attach the module (800) to theirarm(s) (1300) and pull the mounting band (901) and then press the looseend (1301) to an anchor (made of a material such as Velcro) on themounting band (901). This allows the patient to adjust the tension to becomfortable whilst still ensuring that an optimal contact is maintainedacross the Multi-part Non-uniform Pliable Contact Assembly (100).

In addition to the circuitry and elements of the modules describedabove, the system may also have additional sensors, location sensingcircuitry (such as GPS or other current or future equivalent standards);communications circuitry (such as cellular, satellite, Wi-Fi, Bluetoothor other current or future equivalent standards); additional energysources, data storage or external data storage for the detected signalsof the patient's heart, or external/remote processing capabilities. Someof the these additional elements may be, for example, implemented incircuits within the modules or within the housing of the modules or inany known manners. The system may then interact with these additionalelements.

The flexibility of the usable configurations of the invention when usingtwo or three modules is shown in FIGS. 14, 15, 16, 17 and 18, but it isnot limited to the embodiments shown in these examples. The systemmodules (800) can be mounted “outbound” on the externally facing surfaceof each upper arm (1403 and 1404) as shown in FIG. 14 in the front view(1401) and back view (1402). The location utilizes the vascular systemof the patient's arms to conduct the therapeutic shock directly to theheart.

FIG. 15, shows that the modules (800) can also be mounted “inbound” onthe internally facing surface of each upper arm (1501 and 1502) as shownin the front view (1401) and back view (1402). The location utilizes thevascular system of the patient's arms to conduct the therapeutic shockdirectly to the heart. FIG. 16, shows the modules (800) can be mountedunder the arms on the upper chest (1601 and 1602) as shown in the frontview (1401) and back view (1402). An alternate band(s) containing thereference high voltage return lead and digital control link (1405) isutilized to mount and interconnect the modules (800) for thisembodiment. The location utilizes the thoracic cavity conductivepathways of the patient to conduct the therapeutic shock to the heart.

FIG. 17, shows an embodiment where three (3) modules (800) are mountedon the upper chest (1701, 1702 and 1703) as shown in the front view(1401) and back view (1402). An alternate band(s) containing thereference high voltage return lead and digital control link (1405) isutilized to mount and interconnect the modules (800) for thisembodiment. The location utilizes the thoracic pathways of the patientto conduct the therapeutic shock to the heart. The third module providesan additional energy source/reservoir, hence expanding the capability ofthe invention by providing additional/alternate thoracic conductionroutes for delivering the therapeutic pulse as well as an additionalenergy source/reservoir for shaping the nature of the pulse.

FIG. 18, shows an embodiment where the modules (800) are mounted on theupper arm (1801) and the abdominal area (1802), as shown in the frontview (1401) and back view (1402). A combination of bands (901 and 1803)are utilized to mount the modules (800) and the interconnect lead (1405)for this application. The location utilizes the vascular and thoracicpathways of the patient to conduct the therapeutic shock to the heart.In each of the examples shown in FIGS. 14-18, the system with themodules may include or be integrated with a patient wearable adjustableharness or garment or one or more patient wearable adjustable straps tohelp support the system and the modules.

While the foregoing has been with reference to a particular embodimentof the invention, it will be appreciated by those skilled in the artthat changes in this embodiment may be made without departing from theprinciples and spirit of the disclosure, the scope of which is definedby the appended claims.

The invention claimed is:
 1. A wearable automated externaldefibrillator, comprising: two or more defibrillation modules that arewearable on one of a body and a limb of a patient, each defibrillationmodule having a defibrillation subsystem, the two or more defibrillationmodules each having a housing, a power source and an energy reservoir inthe housing and a patient interface assembly integrated into the housingof each defibrillation module, a first defibrillation module generatingmore than one positive pulses of a multiphasic therapeutic pulse and asecond defibrillation module generating more than one negative pulses ofthe multiphasic therapeutic pulse; the patient interface assembly ofeach defibrillation module being wearable on one of a body and a limb ofa patient; each patient interface assembly making contact with a pieceof skin of the patient; and wherein the two or more defibrillationmodules are capable of delivering the multiphasic therapeutic pulse tothe patient through the patient interface assemblies of the two or moredefibrillation modules.
 2. The defibrillator of claim 1, wherein eachdefibrillation module is flexible and conformable to a shape of one ofthe body and the limb of the patient when worn on the one of the bodyand the limb of the patient.
 3. The defibrillator of claim 1, whereineach defibrillation module has a portion of an H-bridge circuit.
 4. Thedefibrillator of claim 3, wherein the two or more defibrillation moduleseach have a portion of an H-bridge circuit so that the portions of theH-bridge circuit form a complete H-bridge circuit.
 5. The defibrillatorof claim 3, wherein the two or more defibrillation modules areelectrically interconnected to each other.
 6. The defibrillator of claim5, wherein the two or more defibrillation modules are electricallyinterconnected to each other through an electrical bus.
 7. Thedefibrillator of claim 5, wherein the two or more defibrillation modulesare electrically interconnected to each other through a dynamicswitching system.
 8. The defibrillator of claim 5, wherein the two ormore defibrillation modules are electrically interconnected directly toeach other.
 9. The defibrillator of claim 1, wherein each defibrillationmodule has an energy level for a predetermined number of therapeuticshocks.
 10. The defibrillator of claim 1, wherein each defibrillationmodule has one of a rechargeable energy source and a replaceable energysource.
 11. The defibrillator of claim 1, wherein each defibrillationmodule has a rechargeable energy source and a replaceable energy source.12. The defibrillator of claim 1, wherein each defibrillation module hasa waterproof housing.
 13. The defibrillator of claim 1, wherein eachpatient interface assembly has an adhesive on or around the patientinterface assembly to help keep the patient interface assembly in placewhile being worn.
 14. The defibrillator of claim 1, wherein thetherapeutic shock is used to treat one of defibrillation, pacing andcardioversion.
 15. The defibrillator of claim 1 further comprising oneor more of a sensor, location sensing circuitry, communicationscircuitry, an additional energy source and data storage.
 16. Thedefibrillator of claim 15 further comprising one or more of an externaldata storage and a remote processing capability.
 17. The defibrillatorof claim 1 further comprising one of a harness, a garment and one ormore adjustable straps.
 18. The defibrillator of claim 1, wherein eachdefibrillation module further comprises at least one controller, atleast one switch, at least one voltage transformer and circuitry in thehousing.
 19. A defibrillation method, comprising: providing two or moredefibrillation modules that are wearable on one of a body and a limb ofa patient wherein each defibrillation module has a housing, adefibrillation subsystem in the housing and at least one patientinterface assembly integrated into the housing of each defibrillationmodule that makes contact with a piece of skin of the patient;generating, collectively by the two or more defibrillation modules eachhaving a power source and an energy reservoir in the housing, amultiphasic therapeutic pulse, wherein a first defibrillation modulegenerates more than one positive pulses of the multiphasic therapeuticpulse and a second defibrillation module generating more than onenegative pulses of the multiphasic therapeutic pulse; and delivering themultiphasic therapeutic pulse to the patient through the patientinterface assemblies of the two or more defibrillation modules.
 20. Themethod of claim 19 further comprising wearing each defibrillation moduleon the one of the body and the limb of the patient.
 21. The method ofclaim 19 further comprising treating one of defibrillation, pacing andcardioversion using the multiphasic therapeutic shock.
 22. Thedefibrillator of claim 1 further comprising a switching circuit thatswitches between the first defibrillation module and the seconddefibrillation module to combine the more than one positive pulses andthe more than one negative pulses to form the generated multiphasictherapeutic pulse.
 23. The method of claim 19, wherein generating themultiphasic therapeutic pulse further comprises switching between thefirst defibrillation module and the second defibrillation module tocombine the more than one positive pulses and the more than one negativepulses to form the generated multiphasic therapeutic pulse.